I tried doing that as well, not for email but intending only to use it to try sharing a second calendar on a second account (my wife's).

The first time I tried I just put the email address and password into the "basic" form where it tries to do all the work for you. That didn't work.

If you click on Advanced Settings you can possibly do it. I looked at my original gmail account and wrote down a few key items (really just the server, I think: m.google.com), then used Advanced Settings to fill out a second account.

When I clicked Save (or Continue or whatever it was) it paused and checked the credentials, then showed me the page where you can select/unselect "Sync Email", "Sync Contacts", and "Sync Calendar".

I unchecked the first two and it works perfectly well, though retrieval of my wife's calendar items did take quite some time the first time (so be patient).

I don't know for sure this would work for either contacts or email but I would assume so... can't think why it wouldn't if calendar works. Still only the primary calendar on each account, but for my purposes that was fine.